As showbiz splits go, the joint announcement from golden couple Tess Daly and Vernon Kay that they were separating after 23 years of marriage came as a genuine shock to many.

But not to me.

Vernon showed his true colours back in 2010, when he was caught sexting glamour model Rhian Sugden – a woman he had met at a Manchester nightclub – sending and receiving what appeared to be a stream of lurid and ‘explicit’ messages.

Rhian, the topless model, sold her story to a red-top newspaper and Tess was forced to endure one of the most humiliating experiences imaginable for any woman: public betrayal.

All the while, she was expected to put on a brave face as Vernon insisted there had never been a physical affair, describing the messages as a ‘stupid decision’ while begging both his wife and his fans for forgiveness.

Those close to the couple said the relationship was rocky for a year afterwards. Yet Tess – the mother of his two daughters – forgave him. In hindsight, she should have run for the hills the moment she discovered her husband was a secret sexter. That should have been the moment she realised he could not be trusted.

But Tess chose to believe Vernon’s insistence that he and Rhian never had sex, and, eventually, the ice thawed and the marriage survived.

But here’s the crucial part: like any cheating man taken back by a forgiving wife, Vernon should then have decided to spend the rest of his life making amends – grovelling every day for both his betrayal and the public humiliation he inflicted on Tess and their daughters.

But according to recent reports, Vernon has over the years become less 'devoted husband' and more 'ageing party boy', preferring nights out with the lads to evenings at home. That image has only been reinforced by his ‘BBC Dance Sounds of the 90s’ live tour, which has seen him touring clubs and arenas across the UK this year.

Even so, in the fragile, febrile world of celebrity, Tess and Vernon have appeared rock-solid since that blip: perfectly compatible, joyous in each other’s company.

Both proud working-class kids who started in TV around the same time and became famous together, they now enjoy a combined fortune of £5million, a fabulous Buckinghamshire home and glittering careers – she fronting Strictly Come Dancing for 21 years on a reported £400,000 per series, Vernon earning £395,000 as host of Radio 2’s mid-morning show and becoming one of the BBC’s highest-paid stars.

And now suddenly it’s all over. Tellingly, they declared in their joint statements: ‘There are no other parties involved in this decision.’

So what has prompted the split of the seemingly happily married couple? It increasingly appears that the behaviour of the searingly egotistical man-child Vernon, who, it seems, is in the middle of a midlife meltdown, is the culprit here.

In the commentary by so-called ‘friends’ surrounding the end of the marriage, much has been made about the age gap between the couple – Tess, at 57, is five years older than Vernon.

We are told that, while the gap did not matter when they were younger, ‘today it appears to be at the heart of their decision to split’. Surely I cannot be the only one detecting a Vernon-friendly narrative in all this?

Apparently, they have ‘aged differently’. He loves going out and having a good time, attending every Oasis concert and partying hard into the night with his daughter Phoebe, 21, who now lives in New York.

Meanwhile, Tess is portrayed as a boring homebody uninterested in hitting the discos in her late 50s. One ‘friend’ – presumably closer to Vernon than to Tess – sneered: ‘Tess isn’t interested in any of that. She is a woman in her late 50s and a bit stiff.’

‘A bit stiff!’ What a horrible thing to say about any woman, let alone a successful, glamorous mum-of-two who stood by Vernon when he behaved abominably and who has been one of the most lovable women on TV for decades – which is more than can be said of her husband.

Sources added: ‘They’ve realised they want different things and to lead different lives from each other.’

One source even commented cattily that what Tess now needs is ‘a wealthy older (rich) man with a yacht’. As if a working-class lass whose parents were factory workers, who built her own fortune through decades of hard work, would be looking for a sugar daddy to fund her lifestyle. The suggestion is beyond insulting to everything she stands for and, frankly, cruel.

No, I have heard stories like these before. It sounds to me like Vernon, once set on being the perfect family man after his affair, finally gave up on grovelling – as cheaters always do. And that Tess finally ditched Vernon when she realised he would never change.

So let us wish Tess every happiness on her own. Although maybe she should have realised all those years ago, when Vernon showed his true colours, that trust is like virginity – once you’ve lost it, you’ll never get it back.